R. Droual et Pr. Woolcock, SWOLLEN-HEAD-SYNDROME ASSOCIATED WITH ESCHERICHIA-COLI AND INFECTIOUS-BRONCHITIS VIRUS IN THE CENTRAL VALLEY OF CALIFORNIA, Avian pathology, 23(4), 1994, pp. 733-742
A commercial broiler flock in the Central Valley of California experie
nced a sudden increase in mortality due to heavy culling. Clinical sig
ns included a snick, swollen heads and severe depression. Necropsy and
histology revealed tracheitis, rhinitis, facial cellulitis, blepharit
is, episcleritis, otitis media and caseous exudate within the air spac
es of cranial bones. Escherichia coli serotype O78 was isolated from a
ll lesions. Infectious bronchitis virus (Massachusetts serotype) was i
solated from trachea/nasal cavity tissue pool. Adenovirus group 1 was
isolated from trachea/nasal cavity and caecal tonsil tissue pools. Ser
um samples were positive for infectious bronchitis using ELISA and hae
magglutination inhibition tests, but negative for turkey rhinotracheit
is by an ELISA using the British antigen. This case suggests that swol
len head syndrome can be associated with viruses other than pneumoviru
s.